Successful encapsulation of β-glucosidase during the synthesis of siliceous mesostructured materials

BACKGROUNDThe biocatalysis field demands universal' supports able to encapsulate enzymes with a straightforward methodology, and at the same time, capable of retaining their catalytic activity. The employment of siliceous materials for such a purpose is a big challenge because drastic synthesis conditions are required and improved functionalization is needed to increase affinities towards the targeted enzyme. In this work, a compromise between the development of a well-formed mesostructured support and an acceptable enzymatic activity was attempted via the in-situ immobilization approach. RESULTSThe immobilization of -glucosidase (EC 3.2.1.21) from Aspergillus niger was approached using different strategies. After trying to immobilize -glucosidase with a post-synthesis approach, nonhigh loadings were achieved both with covalent linkage (using epoxy activated supports; 3.5 mgE g(-1)) and with noncovalent bonding (using amine-functionalized materials; 7.6 mgE g(-1)). However, when the in-situ approach was attempted, success in reaching the highest enzyme loading (close to 200 mgE g(-1)) was achieved. CONCLUSIONIn this work, the support cages around the in-situ encapsulated enzyme fully prevented its release through the narrow windows connecting cages, achieving a less than 5% release of the initially desorbed protein, as well as a further total absence of leaching. This enabled the biocatalyst to be reused at least eight times more without any loss in activity. (c) 2018 Society of Chemical Industry